Bifurcation and Periodicity in Granular Soils: Implicationsto Geomechanics and Hazard Mitigation

颗粒土中的分岔和周期性：对地质力学和减灾的影响

• 批准号: 8800459
• 负责人: Elias Aifantis
• 金额: $ 14.09万
• 依托单位: Michigan Technological University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-07-01 至 1992-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8800459&HistoricalAwards=false
• 关键词: Bifurcation; Periodicity; Granular; Soils; Implicationsto

The project will construct an internal, length-dependent plastic theory for granular materials to be applied to the study of instability phenomena. Analytical, numerical and experimental evaluation of this concept will be conducted to determine the ability of this approach to provide information on the growth and wave length selection of the associated deformation inhomogeneities. The internal length scale will be introduced either through a Cosserat- type modification characterizing the assymetry of stress, or a gradient-dependent term characterizing the heterogeneity of the plastic flow-rule. The merits and drawbacks of both approaches will be examined and the simplest possible form will be used to study three classes of hazard-related problems: shear banding, surface instabilities, and liquefaction. This work will provide a better understanding of the physical failure processes which are fundamental for the development of appropriate mitigation measures.

该项目将为颗粒材料构建一种内部的、与长度相关的塑性理论，应用于不稳定现象的研究。 将对这一概念进行分析、数值和实验评估，以确定该方法提供有关相关变形不均匀性的增长和波长选择信息的能力。 内部长度尺度将通过表征应力不对称性的 Cosserat 型修改或表征塑性流动规则异质性的梯度相关项来引入。 将检查这两种方法的优点和缺点，并将使用最简单的形式来研究三类与危险相关的问题：剪切带、表面不稳定性和液化。 这项工作将有助于更好地理解物理故障过程，这对于制定适当的缓解措施至关重要。